Like the Planet of the Apes phenomenon, Invasion of the Body Snatchers is one of those evergreen science fiction ideas which keep showing up over and over again. That's in addition to it being one of the great horror movies.

The original book has had four film adaptations, and has inspiring many different stories in all genres of science fiction. Many stories have a prior claim on some of the Body Snatchers' ideas, such as Robert A Heinlein's 1951 book The Puppetmasters and the 1953 3-D movie It Came from Outer Space, but Invasion of the Body Snatchers is without doubt the most famous and accomplished.

The Basic Plot

Earth is being slowly infiltrated and taken over by alien 'vegetable' pods that duplicate people's bodies while they sleep, then destroy the original human being. The duplicates are an exact physical match to their originals, down to the last detail. However, the duplicates' minds are cold and emotionless, in contrast to human warmth and affection. This leads people to believe in the early stages of the invasion that their loved ones are being replaced by doubles.

Fighting back, the heroes of the story have to struggle against both the pod people and their own physical need for sleep in order to survive. But, just as the pod people can impersonate humans, so humans can impersonate the pod people - but you must not show any emotion or they'll be on to you!

Up until this stage the plot is predictable. What really keeps the audience gripped is wondering whether it will be a happy or sad ending. Sometimes the menace is defeated, but sometimes the narrative ends on a bleak note, with the Body Snatchers set to dominate the world.

The Body Snatchers (writer: Jack Finney, 1955)

Jack Finney's archetypal novel was originally named The Body Snatchers, although it is more often reprinted under the full 'Invasion' title. It was serialised in Collier's Magazine in 1954, under the premise 'the Nightmare that Threatens the World!', before later being published in book form.

The story deals with events in a small US town which is slowly being infiltrated by aliens, who are using it to launch their eventual conquest of Earth. The book is written in first person from the point of view of Dr Miles Bennel, who frequently appears to be more like a 1950s private detective than a doctor. The book chronicles his attempts to save the few remaining humans, including his romantic interest, Betty Driscoll, and put a stop to the invasion.

Although later adaptations diverged from the original story, many of the familiar set pieces were established in this book, such as when the heroes are trapped in an office struggling not to fall asleep. This is also the case with the part where the pod people, having taken over the town, line up in organised ranks to take pods to their friends and relations all across the country.

Invasion of the Body Snatchers (director: Don Siegel, 1956)

They come from another world!
- movie poster tagline

Shot in black and white, this movie is the first and most faithful film version of the story. It takes nearly all of its scenes and characters from the book, with Kevin McCarthy as Dr Bennel and Dana Wynter as Betty, although the ending is very different. It has been viewed by many critics as an allegory either against communism or McCarthyism. The director claimed he intended to make nothing more than an alien invasion story.

Invasion of the Body Snatchers (director: Philip Kaufman, 1978)

You'll never close your eyes again.
- movie poster tagline

One of the story's bleakest and most horrific adaptations, this film's plot is relocated to a 1970s post-hippy San Francisco. The hero this time around is public health inspector Matthew Bennell (played by Donald Sutherland). His romantic interest is his laboratory technician, Elizabeth Driscoll (played by Brooke Adams). The pair discover that the spores which have been falling on San Francisco for weeks soon swell into giant pods that duplicate people, turning their original bodies into withered husks.

In addition to the location and character changes, the pod people are developed further within the story. A tramp and his dog accidentally become amalgamated, showing that the transformation process isn't perfect. And after the pod people gain the majority, whenever they detect a real human they react with a pointed finger and piercing scream.

Body Snatchers (director: Abel Ferrera, 1993)

They'd kill... to be you.
- movie poster tagline

Bearing little relation to the versions before it, this slightly obscure adaptation is set on a military base. Matri Malone (played by Gabrielle Anwar) travels to it with her EPA¹ inspector father and the rest of her family to inspect some toxic chemicals. When they get there they discover the personnel on the base are being replaced by aliens. Although the film features the 'point-and-scream' from Kaufman's film, it uses none of the names, characters or locations from the other adaptations. This movie has received very mixed reviews.

The Invasion (director: Oliver Hierschbiegel, 2007)

Do not trust anyone. Do not show emotion. Do not fall asleep.
- movie poster tagline

To date, the most recent adaptation of the Body Snatchers story, this story nominally takes place in Washington DC, though its effects are felt all across the globe. Carol Bennel (played by Nicole Kidman) is the hero, with Ben Driscoll (played by Daniel Craig) as the love interest - a rather neat twist on the Bennel-Driscoll romance that is a recurring theme throughout previous versions of the story.

The alien menace takes on a much different form this time, manifesting itself as an alien bacterium that comes down to Earth on the back of a crashed space shuttle. To begin with, the infection does nothing - however, when the host goes to sleep the bacteria catalyse, erasing the hosts emotional reactions. People who have, or have had, diseases affecting the make up of the brain are immune, but everyone else has to stay awake or risk losing their emotions.

The film was also the first to extend the effects of the invasion worldwide, with wars ending and thousands of lives being saved, lending a moral dilemma to Bennel's attempt to turn the human race back to normal.

The Future?

The Invasion of the Body Snatchers story is not one that lends itself to sequels. Either we beat them or they beat us - there's nowhere for the story to go. As a result, remakes are a relatively rare occurrence compared with other film series, such as Halloween, happening roughly once every 15 to 20 years. Can we expect a new Body Snatchers film? Almost certainly. But it may be a rather long wait.